Abstract: In order to investigate the influence of slot type of inner plate in liquid viscous coupling on hump phenomenon, the relations between the axial force difference on inner plates and the factors such as plate beveled edge, beveled edge height, the position of inner plate were simulated by the FLUENT software. The results showed that the axial force difference on inner plates got its maximum value and the hump phenomenon could be induced easily when the plate belveled edge angle was 30 degree and its height equaled to the thickness of plate. According to the experimental results, the hump phenomenon would occur at a lower differential rotational speed when the edges of inner plates were beveled. Concerning the moving direction of inner plates with beveled edge during hump inducing period, the experimental results showed good agreement with theoretical analysis.